mesh scaling and keeping scale for droppers to use (?)

I've been trying to make a pokemon tycoon and found a mesh that I would like one of my droppers to use. The problem is, it's to small and it won't run along the conveyer belt. How do I make it larger and make the droppers use that scale instead of the original scale? also, does anyone know why it won't go along on the conveyer belt? here's the current script if it helps at all

wait(2)
workspace:WaitForChild("PartStorage")



meshDrop = true
--------------------
-- Mesh Settings: -- [If you want a mesh drop, set meshDrop to true up on top.]
-- Look at the mesh properties and change the inside of the quotes below to the appropriate
-- full link or the rbxasset:// style, doesnt matter which one you see in the mesh you want

meshID = "rbxassetid://476509549"  
textureID = "rbxassetid://476509552"
--------------------


while true do
    wait(1.5) -- How long in between drops
    local part = Instance.new("Part",workspace.PartStorage)
    --part.BrickColor=script.Parent.Parent.Parent.DropColor.Value
    --part.Material=script.Parent.Parent.Parent.MaterialValue.Value
    local cash = Instance.new("IntValue",part)
    cash.Name = "Cash"
    cash.Value = 5 -- How much the drops are worth
    part.CFrame = script.Parent.Drop.CFrame - Vector3.new(0,5,0)
    part.FormFactor = "Custom"
    part.Size=Vector3.new(-7.983, 1.321, 90.132) -- Size of the drops
    if meshDrop == true then
    local m = Instance.new("SpecialMesh",part)
    m.MeshId = meshID
    m.TextureId = textureID
    end
    part.TopSurface = "Smooth"
    part.BottomSurface = "Smooth"
    game.Debris:AddItem(part,20) -- How long until the drops expire
end